Minerals

You passively get 1 mineral every second (although if a person is missing from your team, you gain 2 minerals per second, and if 2 people are missing, you gain 3 minerals per second, etc), If you are missing 10 minerals for an item do not fret, just wait those 10 seconds

Last hitting creeps grants you a nice 30-33 mineral bonus

You get minerals for killing heroes and assisting killing the heroes, but assisting grants less minerals